Investor Bill Hwang set off a storm in the stock market in March when his firm, Archegos Capital Management, and its banks, began liquidating huge positions in blue-chip companies, according to people familiar with the transactions. The sales sent individual stocks swooning and have left at least three banks with major damage. As a family office - a firm generally created to handle the investments of a single wealthy person and a small circle around them - Archegos was essentially unregulated.

The saga of GameStop has attracted the attention of trading platforms, regulators and even the White House. Just weeks ago, major hedge funds were betting big money against the success of GameStop in the form of short sales. But that didn't stop individual investors from taking those bets. Instead, a flood of retail investors joined forces on Reddit's WallStreetBets forum to send GameStop's stock soaring. The moves by some brokers to slow down trading in these stocks raised legitimate cries of unfairness to regular investors.